On Mar 29, 12:54*pm, Bob Hoover wrote:
On Mar 29, 9:17*am, Copperhead wrote:

Oddly enough I've had more fun researching and experimenting with
plans and parts building then I'd ever have thought possible and have
spent very little money so far. Mostly this has been due to the fact I
already have most of my woodworking power tools as well as a lot of
metal cutting and bending tools.

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Dear Joe,

Normally, when you have the option of building from either aluminum or
wood, you would opt for metal but there are a few cases where wood may
prove to be the better choice. *In the mid-1930's Virginias Clark, the
fellow who gave us the Clark-Y airfoil, patented a process of making
plywood called 'Duramold' that was superior to aluminum in several
ways, but especially with regard to compound curves. *Howard Hughes
acquired the rights to the process (I believe through Fairchild
Camera) and used it to produce the HK-1 'Hercules' *-- *which we
generally know as 'the Spruce Goose,' even though it is mostly birch.
The 'K' part of 'HK' referred to Henry J. Kaiser, who was supposed to
assemble the giant flying boat, Hughes to fabricate the parts.

One reason we've never heard much about Dura-mold is because of
fiberglas.... and a small Swiss company that came up with epoxy.
Combine the two and even a back-yard craftsman has the ability to
produce complex parts stronger than steel but weighing as much as two-
thirds less.

-Bob

PS -- I've got a hunch that threads such as this often turn into
something useful.

Bob,

I’d read about the composite construction techniques of the ill named
“Spruce Goose”, but never made a correlation with respect current
fiberglass composite aircraft. Merely at a guess, it would appear that
one would need to make they’re own “duramold” ply (glass) wood while
constructing an airframe.

I certainly agree that such a practice would eliminate the need for
applying fiberglass to foam for panels or coverings. Current vacuum
bagging practices used on KR’s with hand made mold would most
certainly work. Now I’m going to have to do some research and
experimentation to see what epoxy and wood veneer bond together best.

For this, I believe the local boat builder’s and marine plywood supply
distributors are going to be a good information source. I think your
right about the weight savings coupled with enhanced strength of such
a project. It also looks like it would eliminate a lot of glass cloth
as well as grinding and sanding. Very interesting and informational,
thanks.

Regards

Joe S.